Birds

"Chickadee Construction."

A Black-capped Chickadee carries a beak-full of wood chips away while excavating a new nest cavity in a broken off alder trunk.
Behind the lens.
Black-capped Chickadees mate for life, and they prefer to excavate a new nest cavity each year. Both members of the pair excavate, one beak-full at a time, and then the female alone builds a small cup for her eggs to rest in at the bottom of the cavity. While she's incubating, her mate delivers food to her and defends their territory.